5-2-23

Ads-B Alerts

JO 7110.65BB, Change 3, effective July 9, 2026 · Official text on faa.gov

Call Sign Mis-Match (CSMM). A CSMM alert will occur when the transmitted ADS-B Flight Identification (FLT ID) does not match the flight plan aircraft identification. Inform the aircraft of the CSMM.
Phraseology

YOUR ADS-B FLIGHT ID DOES NOT MATCH YOUR FLIGHT PLAN AIRCRAFT IDENTIFICATION.
Duplicate ICAO Address. If the broadcast ICAO address is shared with one or more flights in the same ADS-B Service Area (regardless of altitude), and radar reinforcement is not available, target resolution may be lost on one or both targets.
Note

Duplicate ICAO Address Alerts appear as “DA” and are associated with the Data Block (DB) on STARS systems. Duplicate ICAO Address Alerts appear as “DUP” and are associated with the DB on MEARTS systems. Duplicate ICAO Address Alerts appear as “Duplicate 24-bit Address” at the AT Specialist Workstation on ERAM systems.
If a CSMM or Duplicate ICAO address is jeopardizing the safe execution of air traffic control functions, instruct the aircraft to stop ADS-B transmissions, and notify the OS/CIC.
Phraseology

STOP ADS-B TRANSMISSIONS, AND IF ABLE, SQUAWK THREE/ALFA (code).

Note

Not all aircraft are capable of disengaging the ADS-B transmitter independently from the transponder.